Method for transmitting and receiving data in a wireless communication system and apparatus therefor

ABSTRACT

Provided are a method for a UE to transmit and receive data in a wireless communication system and an apparatus therefor. The UE receives downlink control information from a base station. The downlink control information includes an indicator for configuring the bundling size of a downlink shared channel. The UE receives downlink data from the base station through a downlink shared channel configured based on the downlink control information. The bundling size may be configured based on a value of the indicator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application priority to Provisional Application No. 62/584106 filedon Nov. 9, 2017, No. 62/585532 field on Nov. 13, 2017, No. 62/587505filed on Nov. 17, 2017 and No. 62/590393 filed on Nov. 24, 2017 in USthe entire contents of which is hereby incorporated by reference in itsentirety.

BACKGROUND OF THE INVENTION Field of the invention

The present invention relates to a wireless communication system and,more particularly, to a method of transmitting and receiving data and anapparatus supporting the same.

Related Art

Mobile communication systems have been generally developed to providevoice services while guaranteeing user mobility. Such mobilecommunication systems have gradually expanded their coverage from voiceservices through data services up to high-speed data services. However,as current mobile communication systems suffer resource shortages andusers demand even higher-speed services, development of more advancedmobile communication systems is needed.

The requirements of the next-generation mobile communication system mayinclude supporting huge data traffic, a remarkable increase in thetransfer rate of each user, the accommodation of a significantlyincreased number of connection devices, very low end-to-end latency, andhigh energy efficiency. To this end, various techniques, such as smallcell enhancement, dual connectivity, massive multiple input multipleoutput (MIMO), in-band full duplex, non-orthogonal multiple access(NOMA), supporting super-wideband, and device networking, have beenresearched.

SUMMARY OF THE INVENTION

The present invention provides a method of transmitting and receivingdata in a wireless communication system and an apparatus therefor.

In relation to the method and apparatus, this specification proposes amethod of configuring bundling for a downlink shared channel (e.g.,PDSCH) and an apparatus therefor.

Specifically, this specification proposes a method for dynamicallyconfiguring a bundling size for a downlink shared channel based ondownlink control information (DCI) transmitted by a base station and anapparatus therefor.

Technical objects to be achieved in the present invention are notlimited to the above-described technical objects, and other technicalobjects not described above may be evidently understood by a personhaving ordinary skill in the art to which the present invention pertainsfrom the following description.

In an aspect, a method for a user terminal to transmit and receive datain a wireless communication system includes receiving downlink controlinformation from a base station, wherein the downlink controlinformation comprises an indicator for setting a bundling size of adownlink shared channel and receiving downlink data from the basestation through the downlink shared channel configured based on thedownlink control information, wherein the bundling size is set based ona value of the indicator.

Furthermore, the method further includes receiving configurationinformation including a plurality of bundling size sets, each set havingat least one candidate value for the bundling size, from the basestation.

Furthermore, in an embodiment of the present invention, when the valueof the indicator is “0”, a specific bundling size set having onecandidate value among the plurality of bundling size sets is configuredas a set for setting the bundling size. The bundling size is determinedby a candidate value included in the specific bundling size set.

Furthermore, in an embodiment of the present invention, when the valueof the indicator is “1”, bundling size sets including two candidatevalues among the plurality of bundling size sets are configured as a setfor setting the bundling size.

Furthermore, in an embodiment of the present invention, the bundlingsize is set as one of the two candidate values based on a result of acomparison between the number of physical resource blocks contiguous ina frequency axis and a threshold value.

Furthermore, in an embodiment of the present invention, when the numberof contiguous physical resource blocks is greater than the thresholdvalue, the bundling size is set as a greater value of the two candidatevalues.

Furthermore, in an embodiment of the present invention, when the numberof contiguous physical resource blocks is smaller than the thresholdvalue, the bundling size is set as a smaller value of the two candidatevalues.

Furthermore, in an embodiment of the present invention, the thresholdvalue is a value obtained by dividing a resource block of a bandwidthfor an active bandwidth part (BWP) by 2.

Furthermore, in an aspect, a method for a base station to transmit andreceive data in a wireless communication system includes transmittingdownlink control information to the user equipment, wherein the downlinkcontrol information comprises an indicator for setting a bundling sizeof a downlink shared channel and transmitting downlink data to the userequipment through the downlink shared channel configured based on thedownlink control information, wherein the bundling size is set based ona value of the indicator.

Furthermore, in an aspect, a user equipment transmitting and receivingdata in a wireless communication system includes a radio frequency (RF)module configured to transmit and receive radio signals and a processorfunctionally connected to the RF module. The processor is configured toreceive downlink control information from a base station, wherein thedownlink control information comprises an indicator for setting abundling size of a downlink shared channel and to receive downlink datafrom the base station through the downlink shared channel configuredbased on the downlink control information. Te bundling size is set basedon a value of the indicator.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to help understanding of the present invention, theaccompanying drawings which are included as a part of the DetailedDescription provide embodiments of the present invention and describethe technical features of the present invention together with theDetailed Description.

FIG. 1 is a diagram illustrating an example of an overall systemstructure of NR to which a method proposed in the present specificationmay be applied.

FIG. 2 illustrates a relationship between an uplink frame and a downlinkframe in a wireless communication system to which the method proposed inthe present specification may be applied.

FIG. 3 illustrates an example of a resource grid supported in thewireless communication system to which the method proposed in thepresent specification may be applied.

FIG. 4 shows examples of antenna ports and resource grids for eachnumerology to which a method proposed in this specification may beapplied.

FIG. 5 is a diagram showing an example of a self-contained slotstructure to which a method proposed in this specification may beapplied.

FIG. 6 shows an operational flowchart of a UE which transmits andreceives data in a wireless communication system to which a methodproposed in this specification may be applied.

FIG. 7 shows an operational flowchart of a base station which transmitsand receives data in a wireless communication system to which a methodproposed in this specification may be applied.

FIG. 8 illustrates a block diagram of a wireless communication apparatusaccording to an embodiment of the present invention.

FIG. 9 illustrates a block diagram of a communication apparatusaccording to an embodiment of the present invention.

FIG. 10 is a diagram showing an example of the RF module of a wirelesscommunication apparatus to which a method proposed in this specificationmay be applied.

FIG. 11 is a diagram showing another example of the RF module of awireless communication apparatus to which a method proposed in thisspecification may be applied.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Some embodiments of the present disclosure are described in detail withreference to the accompanying drawings. A detailed description to bedisclosed along with the accompanying drawings is intended to describesome exemplary embodiments of the present disclosure and is not intendedto describe a sole embodiment of the present disclosure. The followingdetailed description includes more details in order to provide fullunderstanding of the present disclosure. However, those skilled in theart will understand that the present disclosure may be implementedwithout such more details.

In some cases, in order to avoid making the concept of the presentdisclosure vague, known structures and devices are omitted or may beshown in a block diagram form based on the core functions of eachstructure and device.

In the present disclosure, a base station has the meaning of a terminalnode of a network over which the base station directly communicates witha terminal. In this document, a specific operation that is described tobe performed by a base station may be performed by an upper node of thebase station according to circumstances. That is, it is evident that ina network including a plurality of network nodes including a basestation, various operations performed for communication with a terminalmay be performed by the base station or other network nodes other thanthe base station. The base station (BS) may be substituted with anotherterm, such as a fixed station, a Node B, an eNB (evolved-NodeB), a basetransceiver system (BTS), or an access point (AP) gNB (next generationNB, general NB, gNodeB). Furthermore, the terminal may be fixed or mayhave mobility and may be substituted with another term, such as userequipment (UE), a mobile station (MS), a user terminal (UT), a mobilesubscriber station (MSS), a subscriber station (SS), an advanced mobilestation (AMS), a wireless terminal (WT), a machine-type communication(MTC) device, a machine-to-Machine (M2M) device, or a device-to-device(D2D) device.

Hereinafter, downlink (DL) means communication from a base station toUE, and uplink (UL) means communication from UE to a base station. InDL, a transmitter may be part of a base station, and a receiver may bepart of UE. In UL, a transmitter may be part of UE, and a receiver maybe part of a base station.

Specific terms used in the following description have been provided tohelp understanding of the present disclosure, and the use of suchspecific terms may be changed in various forms without departing fromthe technical sprit of the present disclosure.

The following technologies may be used in a variety of wirelesscommunication systems, such as code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and non-orthogonalmultiple access (NOMA). CDMA may be implemented using a radiotechnology, such as universal terrestrial radio access (UTRA) orCDMA2000. TDMA may be implemented using a radio technology, such asglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA maybe implemented using a radio technology, such as Institute of electricaland electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX),IEEE 802.20, or evolved UTRA (E-UTRA). UTRA is part of a universalmobile telecommunications system (UMTS). 3rd generation partnershipproject (3GPP) Long term evolution (LTE) is part of an evolved UMTS(E-UMTS) using evolved UMTS terrestrial radio access (E-UTRA), and itadopts OFDMA in downlink and adopts SC-FDMA in uplink. LTE-advanced(LTE-A) is the evolution of 3GPP LTE.

Embodiments of the present disclosure may be supported by the standarddocuments disclosed in at least one of IEEE 802, 3GPP, and 3GPP2, thatis, radio access systems. That is, steps or portions that belong to theembodiments of the present disclosure and that are not described inorder to clearly expose the technical spirit of the present disclosuremay be supported by the documents. Furthermore, all terms disclosed inthis document may be described by the standard documents.

In order to more clarify a description, 3GPP LTE/LTE-A/NR (New RAT) ischiefly described, but the technical characteristics of the presentdisclosure are not limited thereto.

Definition of Terms

eLTE eNB: An eLTE eNB is an evolution of an eNB that supports aconnection for an EPC and an NGC.

gNB: A node for supporting NR in addition to a connection with an NGC

New RAN: A radio access network that supports NR or E-UTRA or interactswith an NGC

Network slice: A network slice is a network defined by an operator so asto provide a solution optimized for a specific market scenario thatrequires a specific requirement together with an inter-terminal range.

Network function: A network function is a logical node in a networkinfra that has a well-defined external interface and a well-definedfunctional operation.

NG-C: A control plane interface used for NG2 reference point between newRAN and an NGC

NG-U: A user plane interface used for NG3 reference point between newRAN and an NGC

Non-standalone NR: A deployment configuration in which a gNB requires anLTE eNB as an anchor for a control plane connection to an EPC orrequires an eLTE eNB as an anchor for a control plane connection to anNGC

Non-standalone E-UTRA: A deployment configuration an eLTE eNB requires agNB as an anchor for a control plane connection to an NGC.

User plane gateway: A terminal point of NG-U interface

General System

FIG. 1 is a diagram illustrating an example of an overall structure of anew radio (NR) system to which a method proposed by the presentdisclosure may be implemented.

Referring to FIG. 1, an NG-RAN is composed of gNBs that provide an NG-RAuser plane (new AS sublayer/PDCP/RLC/MAC/PHY) and a control plane (RRC)protocol terminal for a UE (User Equipment).

The gNBs are connected to each other via an Xn interface.

The gNBs are also connected to an NGC via an NG interface.

More specifically, the gNBs are connected to a Access and MobilityManagement Function (AMF) via an N2 interface and a User Plane Function(UPF) via an N3 interface.

New Rat (NR) Numerology and Frame Structure

In the NR system, multiple numerologies may be supported. Thenumerologies may be defined by subcarrier spacing and a CP (CyclicPrefix) overhead. Spacing between the plurality of subcarriers may bederived by scaling basic subcarrier spacing into an integer N (or μ). Inaddition, although a very low subcarrier spacing is assumed not to beused at a very high subcarrier frequency, a numerology to be used may beselected regardless of a frequency band.

In addition, in the NR system, a variety of frame structures accordingto the multiple numerologies may be supported.

Hereinafter, an Orthogonal Frequency Division Multiplexing (OFDM)numerology and a frame structure, which may be considered in the NRsystem, will be described.

A plurality of OFDM numerologies supported in the NR system may bedefined as in Table 1.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] Cyclic prefix 0 15 Normal 1 30 Normal 260 Normal, Extended 3 120 Normal 4 240 Normal 5 480 Normal 5 480 Normal

Regarding a frame structure in the NR system, a size of various fieldsin the time domain is expressed as a multiple of a time unit ofT_(s)=1/(Δf_(max)·N_(f)). In this case, Δf_(max)=480·10³, andN_(f)=4096. DL and UL transmission is configured as a radio frame havinga section of T_(f)=(Δf_(max)N_(f)/100)·T_(s)=10 ms. The radio frame iscomposed of ten subframes each having a section ofT_(sf)=(Δf_(max)N_(f)/1000)·T_(s)=1 ms. In this case, there may be a setof UL frames and a set of DL frames.

FIG. 2 illustrates a relationship between a UL frame and a DL frame in awireless communication system to which a method proposed by the presentdisclosure may be implemented.

As illustrated in FIG. 2, a UL frame number I from a User Equipment (UE)needs to be transmitted T_(TA)=N_(TA)T_(s) before the start of acorresponding DL frame in the UE.

Regarding the numerology μ, slots are numbered in ascending order ofn_(s) ^(μ)∈{0, . . . , N_(subframe) ^(slots, μ)−1} in a subframe, and inascending order of n_(s,f) ^(μ)∈{0, . . . , N_(frame) ^(slots,μ)−1} in aradio frame. One slot is composed of continuous OFDM symbols of N_(symb)^(μ), and N_(symb) ^(μ) is determined depending on a numerology in useand slot configuration. The start of slots n_(s) ^(μ) in a subframe istemporally aligned with the start of OFDM symbols n_(s) ^(μ)N_(symb)^(μ) in the same subframe.

Not all UEs are able to transmit and receive at the same time, and thismeans that not all OFDM symbols in a DL slot or an UL slot are availableto be used.

Table 2 shows the number of OFDM symbols per slot for a normal CP in thenumerology μ, and Table 3 shows the number of OFDM symbols per slot foran extended CP in the numerology μ.

TABLE 2 Slot configuration 0 1 μ N_(symb) ^(μ) N_(frame) ^(slots, μ)N_(subframe) ^(slots, μ) N_(symb) ^(μ) N_(frame) ^(slots, μ)N_(subframe) ^(slots, μ) 0 14 10 1 7 20 2 1 14 20 2 7 40 4 2 14 40 4 780 8 3 14 80 8 — — — 4 14 160 16 — — — 5 14 320 32 — — —

TABLE 3 Slot configuration 0 1 μ N_(symb) ^(μ) N_(frame) ^(slots, μ)N_(subframe) ^(slots, μ) N_(symb) ^(μ) N_(frame) ^(slots, μ)N_(subframe) ^(slots, μ) 0 12 10 1 6 20 2 1 12 20 2 6 40 4 2 12 40 4 680 8 3 12 80 8 — — — 4 12 160 16 — — — 5 12 320 32 — — —

NR Physical Resource

Regarding physical resources in the NR system, an antenna port, aresource grid, a resource element, a resource block, a carrier part,etc. may be considered.

Hereinafter, the above physical resources possible to be considered inthe NR system will be described in more detail.

First, regarding an antenna port, the antenna port is defined such thata channel over which a symbol on one antenna port is transmitted can beinferred from another channel over which a symbol on the same antennaport is transmitted. When large-scale properties of a channel receivedover which a symbol on one antenna port can be inferred from anotherchannel over which a symbol on another antenna port is transmitted, thetwo antenna ports may be in a QC/QCL (quasi co-located or quasico-location) relationship. Herein, the large-scale properties mayinclude at least one of delay spread, Doppler spread, Doppler shift,average gain, and average delay.

FIG. 3 shows an example of a resource grid supported in a wirelesscommunication system to which a method proposed in this specificationmay be applied.

FIG. 3 illustrates an example in which a resource grid includes N_(RB)^(μ)N_(sc) ^(RB) subcarriers on the frequency domain and one subframeincludes 14·2μ OFDM symbols, but the present invention is not limitedthereto.

In the NR system, a transmitted signal is described by one or moreresource grids including N_(RB) ^(μ)N_(sc) ^(RB) subcarriers and2^(μ)N_(symb) ^((μ)) OFDM symbols. In this case, N_(RB) ^(μ)≤N_(RB)^(max, μ). The N_(RB) ^(max, μ) indicates a maximum transmissionbandwidth, which may be different between numerologies and betweenuplink and downlink.

In this case, as in FIG. 4, one resource grid may be configured for eachnumerology μ and antenna port p.

FIG. 4 shows examples of antenna ports and resource grids for eachnumerology to which a method proposed in this specification may beapplied.

Each element of the resource grid for the numerology μ and the antennaport p is indicated as a resource element, and may be uniquelyidentified by an index pair (k,l). Herein k=0, . . . , N_(RB) ^(μ)N_(sc)^(RB)−1 is an index in the frequency domain, and l=0, . . .,2^(μ)N_(symb) ^((μ))−1 indicates a location of a symbol in a subframe.To indicate a resource element in a slot, the index pair (k, l) is used.Herein, l=0, . . . ,N_(symb) ^(μ)−1.

The resource element (k, l) for the numerology μ and the antenna port pcorresponds to a complex value a_(k, l) ^((p, μ)). When there is no riskof confusion or when a specific antenna port or numerology is specified,the indexes p and μ may be dropped and thereby the complex value maybecome a_(k,l) ^((p)) or a_(k,l) .

In addition, a physical resource block is defined as N_(sc) ^(RB)=12continuous subcarriers in the frequency domain. In the frequency domain,physical resource blocks may be numbered from 0 to N_(RB) ^(μ)−1. Atthis point, a relationship between the physical resource block numbern_(PRB) and the resource elements (k, l) may be given as in Equation 1

$\begin{matrix}{n_{PRB} = \lfloor \frac{k}{N_{sc}^{RB}} \rfloor} & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

In addition, regarding a carrier part, a UE may be configured to receiveor transmit the carrier part using only a subset of a resource grid. Atthis point, a set of resource blocks which the UE is configured toreceive or transmit are numbered from 0 to N_(URB) ^(μ)−1 in thefrequency region.

Beam Management

In NR, beam management is defined as follows.

Beam management: a set of L1/L2 procedures for obtaining and maintaininga set of TRP(s) and/or UE beams which may be used for DL and ULtransmission and reception, and includes at least the followingcontents:

Beam determination: an operation for a TRP(s) or a UE to select its owntransmission/reception beam.

Beam measurement: an operation for a TRP(s) or a UE to measure thecharacteristics of a received beamforming signal.

Beam reporting: an operation for a UE to report information of abeamformed signal based on beam measurement.

Beam sweeping: an operation of covering a space region using beamstransmitted and/or received at time intervals according to apredetermined method.

Furthermore, a Tx/Rx beam correspondence in a TRP and a UE is defined asfollows.

A Tx/Rx beam correspondence in a TRP is maintained when at least one ofthe followings is satisfied.

A TRP may determine a TRP reception beam for uplink reception based onthe downlink measurement of a UE for one or more Tx beams of the TRP.

A TRP may determine a TRP Tx beam for downlink transmission based on theuplink measurement of the TRP for one or more Rx beams of the TRP.

A Tx/Rx beam correspondence in a UE is maintained when at least one ofthe followings is satisfied.

A UE may determine a UE Tx beam for uplink transmission based on thedownlink measurement of the UE for one or more Rx beams of the UE.

A UE may determine a UE Rx beam for downlink reception based on theindication of a TRP based on uplink measurement for one or more Txbeams.

Capability indication of UE beam correspondence-related information issupported by a TRP.

The following DL L1/L2 beam management procedure is supported within oneor multiple TRPs.

P-1: it is used to enable UE measurement for a different TRP Tx beam inorder to support the selection of a TRP Tx beam/UE Rx beam(s).

In the case of beamforming in a TRP, in general, intra/inter-TRP Tx beamsweep is included in a different beam set. For beamforming in a UE, ittypically includes UE Rx beam sweep from a set of different beams.

P-2: UE measurement for a different TRP Tx beam is used to change aninter/intra-TRP Tx beam(s).

P-3: if a UE uses beamforming, UE measurement for the same TRP Tx beamis used to change a UE Rx beam.

Aperiodic reporting triggered by at least network is supported in theP-1, P-2 and P-3-related operations.

UE measurement based on an RS for beam management (at least CSI-RS)includes K (a total number of beams) beams. A UE reports the measurementresults of selected N Tx beams. In this case, N is not essentially afixed number. A procedure based on an RS for a mobility object is notexcluded. Reporting information includes information indicating ameasurement quantity for an N beam(s) when at least N<K and N DLtransmission beams. In particular, a UE may report CSI-RS resourceindicator (CRI) of N′ with respect to K′>1 non-zero-power (NZP) CSI-RSresources.

The following higher layer parameters may be configured in a UE for beammanagement.

N≥1 reporting setting, M≥1 resource setting

Links between reporting setting and resource setting are established inan agreed CSI measurement configuration.

CSI-RS-based P-1 and P-2 are supported as resource and reportingsetting.

P-3 may be supported regardless of whether reporting setting is presentor not.

Reporting setting including at least the following contents.

Information indicating a selected beam

L1 measurement reporting

Time domain operation (e.g., an aperiodic operation, a periodicoperation, a semi-persistent operation)

Frequency granularity when several frequency granularities are supported

Resource setting including at least the following contents

Time domain operation (e.g., an aperiodic operation, a periodicoperation, a semi-persistent operation)

RS type: at least NZP CSI-RS

At least one CSI-RS resource set. Each CSI-RS resource set includes K≥1CSI-RS resources (some parameters of the K CSI-RS resources may be thesame. For example, a port number, a time domain operation, density and aperiod)

Furthermore, NR supports the following beam reporting by taking intoconsideration L groups where L>1.

Information indicating a minimum group

Measurement quantity for an N1 beam (L1 RSRP and CSI reporting support(if a CSI-RS is for CSI acquisition))

Information indicating N1 DL transmission beams if applicable

Beam reporting based on a group, such as that described above, may beconfigured in a UE unit. Furthermore, the group-based beam reporting maybe turned off in a UE unit (e.g., when L=1 or N1=1).

NR supports that a UE can trigger a mechanism for recovery from a beamfailure.

A beam failure event occurs when quality of a beam pair link of anassociated control channel is sufficiently low (e.g., a comparison witha threshold value, the timeout of an associated timer). A mechanism forrecovery from a beam failure (or obstacle) is triggered when a beamobstacle occurs.

A network explicitly configures a UE having resources for transmittingan UL signal for a recovery object. The configuration of resources issupported at the place where a base station listens from some or all ofdirections (e.g., random access region).

An UL transmission/resource reporting a beam obstacle may be located atthe same time instance as a PRACH (resource orthogonal to a PRACHresource) and at a time instance different from that of a PRACH(configurable with respect to a UE). The transmission of a DL signal issupported so that a UE can monitor a beam in order to identify newpotential beams.

NR supports beam management regardless of a beam-related indication. Ifa beam-related indication is provided, information regarding a UE-sidebeamforming/reception procedure used for CSI-RS-based measurement may beindicated with respect to the UE through QCL. It is expected thatparameters for delay, Doppler, an average gain, etc. used in the LTEsystem and a spatial parameter for beamforming in a reception stage willbe added as QCL parameters to be supported in NR. An angle ofarrival-related parameter may be included in the UE Rx beamformingviewpoint and/or angle of departure-related parameters may be includedin the base station reception beamforming viewpoint. NR supports the useof the same or different beams in a control channel and correspondingdata channel transmission.

For NR-PDCCH transmission supporting the robustness of beam pair linkblocking, a UE may configure an NR-PDCCH on M beam pair links at thesame time. In this case, a maximum value of M≥1 and M may depend on atleast the UE capability.

A UE may be configured to monitor an NR-PDCCH on a different beam pairlink(s) in different NR-PDCCH OFDM symbols. A parameter related to a UERx beam configuration for monitoring an NR-PDCCH on multiple beam pairlinks may be configured by higher layer signaling or a MAC CE and/or istaken into consideration in the search space design.

At least NR supports the indication of a spatial QCL assumption betweena DL RS antenna port(s) and a DL RS antenna port(s) for the demodulationof a DL control channel. A candidate signaling method for the beamindication of an NR-PDCCH (i.e., a configuration method of monitoring anNR-PDCCH) is MAC CE signaling, RRC signaling, DCI signaling, spec.transparent and/or implicit method, and a combination of those signalingmethods.

For the reception of a unicast DL data channel, NR supports theindication of a spatial QCL assumption between a DL RS antenna port andthe DMRS antenna port of a DL data channel.

Information indicating an RS antenna port is indicated through DCI(downlink grant). Furthermore, the information indicates an RS antennaport QCLed with a DMRS antenna port. A different set of DMRS antennaports for a DL data channel may be indicated as QCL with a different setof RS antenna ports.

Hereinafter, prior to detailed description of methods proposed in thisspecification, contents directly/indirectly related to the methodsproposed in this specification are described in brief below.

In next-generation communication, such as 5G, New Rat (NR), as morecommunication devices require a greater communication capacity, thereemerges a need for enhanced mobile broadband communication compared tothe existing radio access technology (RAT).

Furthermore, massive machine type communications (MTC) providing variousservices anywhere and at any time by connecting multiple devices andthings is also one of important issues to be taken into consideration inthe next-generation communication.

Furthermore, the design or structure of a communication system in whichservices and/or UEs sensitive to reliability and latency are taken intoconsideration is also discussed.

As described above, the introduction of a next-generation radio accesstechnology (RAT) in which enhanced mobile broadband (eMBB)communication, massive MTC (mMTC) and ultra-reliable and low latencycommunication (URLLC) are taken into consideration is now discussed. Inthis specification, a corresponding technology is commonly called “newRAT(NR)”, for convenience sake.

Self-Contained Slot Structure

In order to minimize latency of data transmission in the TDD system, aself-contained slot structure, such as FIG. 5, is taken intoconsideration in a 5-generation New RAT (NR).

That is, FIG. 5 is a diagram showing an example of a self-contained slotstructure to which a method proposed in this specification may beapplied.

In FIG. 5, a slashed region 510 indicates a downlink control region, anda black part 520 indicates an uplink control region.

A part 530 having no indication may be used for downlink datatransmission and may be used for uplink data transmission.

The characteristics of such a structure is that DL transmission and ULtransmission are sequentially performed within one slot and DL data istransmitted and UL Ack/Nack may also be transmitted and received withinone slot.

Such a slot may be defined as a “self-contained slot.”

That is, through such a slot structure, a base station can reduce thetime taken for data retransmission to a UE when a data transmissionerror occurs, thereby being capable of minimizing latency of the finaldata delivery.

In such a self-contained slot structure, a base station and a UE requirea time gap for a process from a transmission mode to a reception mode ora process from the reception mode to the transmission mode.

To this end, in the corresponding slot structure, some OFDM symbols atan instance from DL to UL is configured as a guard period (GP).

In the following specification, a method of configuring and/orindicating a physical resource block bundling size applied to a downlinkshared channel (e.g., a physical downlink shared channel (PDSCH)) inrelation to the transmission and reception of downlink data is describedbelow specifically.

PRB bundling may mean an operation of applying the same PMI across aplurality of contiguous resource blocks (i.e., physical resource block(PRB)) when data transmission is performed. In other words, PRB bundlingmay mean that a UE assumes multiple resource blocks on the frequencydomain as one granularity for precoding in order to perform PMIreporting and/or RI reporting.

Furthermore, PRB bundling for a downlink shared channel may mean orrefer to demodulation reference signal bundling (DMRS bundling).

In this case, a system bandwidth or bandwidth part (BWP) may be splitbased on the size (e.g., P′ or P′_(Bwp,i)) of a precoding resource blockgroup (PRG). Each PRG may include contiguous PRBs (or consecutive PRB).That is, a PRB bundling size described in this specification may meanthe size of a PRB or a PRG value. Furthermore, a value (i.e., number)indicating a PRB bundling size may mean the number of PRBs forcorresponding PRB bundling.

In this case, the setting of the size of PRB bundling needs to bedetermined by taking into consideration a tradeoff between theflexibility of precoders used in a PRB and quality of channelestimation. Specifically, if the size of PRB bundling is set very large,a disadvantage of a flexibility aspect may be caused depending on thatthe same precoder must be used in all PRBs. In contrast, if the size ofPRB bundling is set very small, complexity in channel estimation mayincrease. Accordingly, to set the size of PRB bundling needs to beefficiently performed by taking into consideration the above-describedaspects.

In relation to the transmission of downlink data, in the NR system, thevalue of a PRB bundling size may be set according to a method ofselecting a specific value of preset values (e.g., 1, 2, 4, 8, 16) asthe value of a PRB bundling size (hereinafter, a first method) and/or amethod of setting the same value as bandwidth (or PRBs) contiguouslyscheduled (i.e., allocated) with respect to a corresponding UE on thefrequency domain as the value of a PRB bundling size (hereinafter, asecond method). In this case, the first method and the second method maybe independently applied or the two methods may be mixed and applied.

For example, if a PRB bundling size set is configured as {2, 4, UEallocation band (e.g., wideband)}, a PRB bundling size may be selected(or determined) as any one value of 2 or 4 according to the firstmethod. Alternatively, in this case, the PRB bundling size may beselected as a UE allocation band according to the second method.

In this case, if a PRB bundling size set includes a candidate value,such as {2, 4, UE allocation band (e.g., wideband)}, a PRB bundling sizemay be indicated through 1-bit information of a DCI field as follows.

For example, when the 1 bit of the DCI field indicates a value of “1”, aPRB bundling size may be determined as one or two candidate values setby RRC.

In this case, if two candidate values are set by RRC, a PRB bundlingsize may be implicitly determined as one value based on a scheduledbandwidth, a resource block group, a subband size, a PDCCH resourceelement group bundling size, a bandwidth part, a DMRS pattern, etc.

When the 0 bit of a DCI field indicates a value of “0”, a PRB bundlingsize may be set as a value set by RRC.

If a resource block group (RBG)=2 is configured in a UE, the UE does notexpect the value of a PRG as “4.”

In a wide range bandwidth, a set of RBG sizes may include at leastvalues of 2, [3,] 4, [6,] 8, 16. The RBG size may be different dependingon the number of symbols for data.

An RBG size may be determined by a network channel bandwidth, abandwidth for a configured bandwidth part, a network or downlink controlinformation.

Resource allocation of uplink/downlink may be configured like Table 4and may be selected by RRC.

TABLE 4 Config 1 Config 2 X0 − X1 RBs RBG size 1 RBG size 2 X1 + 1 − X2RBs RBG size 3 RBG size 4 . . . . . . . . .

RRC may select Config 1 or Config 2. One config may be configured as adefault value when RRC configures another config.

A configuration for uplink/downlink is separate, but the same table maybe used and the same RBG size may be used regardless of duration.

In relation to such contents, in the NR system, a method of indicating aPRB bundling size through a 1-bit value is taken into consideration. Inthis case, as described above, when an indicator indicating the bundlingsize of a DCI field is “0”, one value set by RRC may be set as abundling size.

However, when the value of an indicator indicating a bundling size inthe DCI field is “1”, two values has been set by RRC. In this case, amethod of implicitly configuring a bundling size of the two values needsto be taken into consideration.

An embodiment of the present invention proposes an implicitdetermination method of dynamically indicating a bundling size when thevalue of an indicator indicating a bundling size is “1” by taking intoconsideration the above description.

The following embodiments have been classified for convenience ofdescription only, and some elements or characteristics of any embodimentmay be included in another embodiment or may be substituted withcorresponding elements or characteristics of another embodiment.

For example, the contents of a PRB bundling size set described in thefirst embodiment may be applied to various embodiments of thespecification in common.

Furthermore, for the configuration and/or indication of PRB bundling,methods described in the first embodiment to the fourth embodiment(e.g., a method for common downlink data) and a method described in afifth embodiment (e.g., a method for broadcast downlink data) may beapplied independently or in combination and vice versa.

<Embodiment 1> when a value of an indicator indicating a bundling sizeis “1”, the bundling size may be determined based on the number ofresource blocks allocated for a UE for PDSCH transmission.

Specifically, when the number of resource blocks allocated for PDSCHtransmission is greater than a reference number (e.g., a specificthreshold value), a greater value of candidate values included in thecandidate value set of a bundling size configured by RRC may be set as abundling size.

Alternatively, a bundling size may be implicitly configured by comparinga maximum value or minimum value of the number contiguously neighboringresources among resource blocks allocated to a UE for PDSCH transmissionwith a reference RB value (or threshold value) instead of the number ofallocated resource blocks.

For example, if resource blocks allocated to a UE are (1,2,3), (6,7),and (10), a maximum value of the number of contiguously neighboringresources is 3 and a minimum value thereof is 1.

In this case, the UE may compare a maximum value or minimum value with athreshold value, and may set one of the candidate values of a bundlingsize, configured by RRC, as a bundling size based on a result of thecomparison.

The “number of allocated resource blocks”, a “maximum value or minimumvalue of the number of contiguously neighboring resource blocks amongallocated resource blocks” and a “reference number (or threshold value)”may be separately set by a network through higher layer RRC signaling. Abase station may indicate whether any of the number of allocatedresource blocks, and a maximum value and minimum value of the number ofcontiguously neighboring resource blocks among allocated resource blockwill be set as a bundling size by comparing the values with a thresholdvalue through RRC signaling with respect to a UE.

Embodiment 1-1

In the embodiment 1, a reference number (or threshold value) fordetermining a bundling size may be determined based on the bandwidth ofan active bandwidth part, an active bandwidth part size or a bandwidthpart size N_(BWP 1) ^(size).

For example, if 50 RBs are used in a carrier BWP 1, when an allocatedresource is 10 RBs or more, a greater value of sets {2, 4}, {2,scheduled bandwidth (BW)}, and {4, scheduled bandwidth}, that is, acandidate value set of a bundling size configured by RRC is set (ordetermined) as a bundling size.

In this case, regardless of the number of RBs allocated for datatransmission, a UE and a base station may assume the value of ascheduled bandwidth as a value greater than 2 or 4 and determine thebundling size.

If 100 RBs are used in a BWP 2, a threshold value may be changeddifferently from a BWP 1. When an allocated resource is 20 RBs or more,a greater value of a candidate value set of a bundling size may be setas a bundling size.

That is, a threshold value, that is, a reference RB number fordetermining a bundling size, may be a value obtained by dividing each ofthe bandwidth of an active bandwidth part, an active bandwidth part sizeor bandwidth part size N_(BWP 1) ^(size) by 2 as in Equation 2.

Threshold value=N_(BWP 1) ^(size)/2  [Equation 2]

In Equation 2, the threshold value may be set as a rounding-up value,rounding-off value or half-rounding-up value of a value obtained bydividing each of the bandwidth of the active bandwidth part, an activebandwidth part size or a bandwidth part size, N_(BWP 1) ^(size) by 2.

If a bundling size is determined based on the number of allocated RBs,when the number of allocated RBs is small, a diversity effect can beobtained by performing precoder cycling through a small bundling size.

A threshold value, that is, the number of RBs that is a reference, maybe determined based on a system bandwidth, the bandwidth of a componentcarrier or a UE-specific bandwidth.

Alternatively, if multiple active BWPs of BWPs configured for a UEneighbor contiguously or discontiguously, a threshold value may bedetermined based on a total number, minimum value or maximum value ofBWs of each active BWP when a PDSCH is transmitted through one DCIconfiguration in multiple activated BWPs.

For example, if 10 RBs are used in an active BWP 1 and 20 RBs are usedin an active BWP 2, a threshold value may be determined based on 30 RBs,that is, a total number, 10 RBs, that is, a minimum value, or 20 RBs,that is, a maximum value, of the BW.

Embodiment 1-2

Unlike in the embodiment 1-1, a threshold value may be determined basedon an RBG size. For example, if an RBG size is {1, 2, 4}, when anallocated resource is 10 RBs or more, a greater value of sets {2, 4},{2, scheduled bandwidth (BW)} and {4, scheduled bandwidth}, that is, acandidate value set of a bundling size, is set (or determined) as abundling size.

However, if an RBG size is {8, 16}, when a threshold value is changedand thus an allocated resource is 20 RBs or more, a greater value ofsets {2, 4}, {2, scheduled bandwidth (BW)} and {4, scheduled bandwidth},that is, a candidate value set of a bundling size, may be set (ordetermined) as a bundling size.

If the method described in the proposal 1-1, 1-2 is used, when thenumber of allocated RBs is small, a diversity effect can be obtained byperforming precoder cycling through a smaller bundling size.

That is, if the bundling size of a PRB is flexibly set, the size ofbundling can be set based on a value of an indicator indicating thebundling size of a DCI field in the proposals 1 to 1-2.

In this case, a UE may obtain candidate value sets, including candidatevalues of a bundling size, through RRC signaling from a base station.

Specifically, when a value of DCI is “0”, a UE may select a candidatevalue set including a candidate value of the sets of candidate valueswhen it receives a PDSCH scheduled by the same DCI, and may set thevalue, included in the selected candidate value set, as a bundling size.

When the value of DCI is “1”, the UE selects a candidate value setincluding one or more candidate values among the sets of candidatevalues when it receives a PDSCH scheduled by the same DCI.

If one or more values are included in the selected candidate value set,the UE may select one of two values and set the selected value as thesize of bundling.

In this case, to select one of the two values may be implicitlyindicated with respect to the UE.

Specifically, when the number of contiguous PRBs is greater than theabove-described threshold value, the UE may set a greater value ofvalues included in a candidate value set as a bundling size. If not, theUE may set a smaller value as a bundling size.

For example, if a candidate value set is {2, wideband} or {4, wideband},a UE may set a wideband value as a bundling size when the number ofcontiguously contiguous PRBs is greater than a threshold value, and mayset 2 or 4 as a bundling size if not.

Proposal 2

When a value of an indicator indicating a bundling size is “1”, thebundling size may be implicitly determined based on a resourceallocation type configured in a UE.

Specifically, in LTE, the allocation of downlink resources may bedifferently configured based on the type. That is, a resource allocationtype for the configuration of a downlink resource may be defined as 0, 1or 2.

In the resource allocation type 0, resources are allocated in an RBGunit based on a BWP. In the resource allocation type 1, resources areallocated by notifying a UE of RBs in which downlink transmission occurswithin a subset including contiguous RBGs according to a BWP through abitmap. In the resource allocation type 2, contiguous RB resources areallocated by notifying a UE of an RB number and length where resourceallocation starts. The resource allocation type 2 may be divided intolocalized transmission and distributed transmission.

In the case of the localized transmission of the resource allocationtype 2, contiguous RB resources are allocated to a UE without anychange. In the case of the distributed transmission of the resourceallocation type 2, RBs are uniformly distributed to the frequency domainbased on a gap size according to a BWP and allocated to a UE.

In NR downlink, localized resource allocation of the resource allocationtype 0 and 2 in LTE can be supported. Distributed resource allocation ofthe type 2 can also be supported. Accordingly, a bundling size may beimplicitly configured based on a resource allocation type allocated to aUE.

Proposal 2-1

In the resource allocation type 0 described in the proposal 2, if acandidate value set of a bundling size configured by RRC is {2,4} and{2, scheduled BW}, when an RBG size is {1, 2}, a bundling size is set asa smaller value. When the RBG size is {4, 8, 16}, a bundling size is setas a greater value.

Furthermore, if a candidate value set is {4, scheduled BW}, a bundlingsize is set as a smaller value when the size of an RBG is {1, 2, 4}, anda bundling size is set as a greater value when the RBG size is {8, 16}.

In this case, if the size of contiguously allocated RBGs is great, highchannel estimation performance can be obtained using a large number ofDMRS symbols neighboring in the frequency domain.

The proposal 2-1 is a method for configuring a bundling size when aresource allocation type is “0”, but is not limited thereto. Theproposal 2-1 may also be applied to a method for configuring a bundlingsize regardless of a resource allocation type.

An active BWP may be flexibly changed through MAC signaling. The RBG ofa UE (determined as the size of an active BWP) may be flexibly changed.As a result, a bundling size may be flexibly changed.

Proposal 2-2

If a resource allocation type is the type 2 and distributed transmissionis configured as DCI, a smaller value is set as a bundling size in eachof candidate value sets {2,4}, {2, scheduled BW}, and {4, scheduled BW}configured by RRC.

The distributed transmission of the resource allocation type 2 is amethod of allocating discontiguous RB resources uniformly distributed inthe frequency domain based on a BWP. Accordingly, to set a bundling sizegreatly may be meaningless because the possibility that a coherentfrequency will be broken for each allocated RB is good.

In the resource allocation type 2, if the distributed transmission isconfigured, a UE may neglect an indicator (field value) indicating abundling size in DCI, and may assume the smallest value in a candidatevalue set as a bundling size or not apply bundling.

That is, the UE may make off PRB bundling so that a different precoderis applied for each RB.

Proposal 2-3

If a resource allocation type is the type 2 and the localizedtransmission is configured as DCI, a greater value in each of candidatevalue sets {2,4}, {2, scheduled BW}, and {4, scheduled BW} configured byRRC is set as a bundling size.

In this case, high channel estimation performance can be obtained as inthe proposal 2-1 using a large number of DMRS symbols neighboring in thefrequency domain from contiguously allocated RBs.

Alternatively, a method of setting a bundling size using the method ofthe proposal 1 in the case of the localized transmission of the resourceallocation type 2 and determining a bundling size according to theresource allocation type described in the proposal 2 in the remainingresource allocation types may be used.

Proposal 3

Unlike in the proposal 1 and the proposal 2, if an indicator related tothe bundling size of DCI has a value of “1”, a bundling size may be setbased on the number of layers among multiple antenna informationconfigured in a UE through the DCI.

For example, if the number of layers configured through DCI is 2 orless, a greater value in each of {2,4}, {2, scheduled BW}, and {4,scheduled BW}, that is, candidate value sets configured by RRC, may beset as a bundling size.

If the number of layers configured by DCI is 3 or more, a smaller valuein each of candidate value sets may be set as a bundling size.

When the SNR is fixed, to increase the number of layers means anincrease in the number of independent transmission and reception paths.Accordingly, a total number of transmission and reception paths may alsoincrease.

If the transmission and reception path increases, frequency selectivityof a transmission and reception channel may increase due to an increasein delay spread.

If frequency selectivity of a channel is great, a frequency selectivegain can be obtained through a small bundling size.

Proposal 4

When an indicator related to the bundling size of DCI has a value of“1”, a UE scheduled with multi user (MU)-MIMO sets a smaller value ineach of candidate value sets {2,4}, {2, scheduled BW}, and {4, scheduledBW}, configured by RRC, as a bundling size.

If an RB allocated with SU and an RB allocated with MU-MIMO, among RBsallocated to a UE, coexist, a large bundling size may become an obstaclein applying an efficient precoder to each RB.

For example, if a scheduled BW is 10 RBs, an RB allocated with MU-MIMOis 1 RB, and an RB allocated with SU is 9 RBs, when a bundling size isset as 10 RBs, that is, a scheduled BW, and a Zero-Forcing precoder isfully used in a BW scheduled for the 1 RB allocated with MU-MIMO,beamforming not necessary for 9 RBs allocated with SU may be performed.

In this case, if a small bundling size, such as 2 or 4, is set, thenumber of RBs on which beamforming is unnecessarily performed can bereduced.

A UE receives DMRS port information of another UE, co-schedule withMU-MIMO, or DMRS CDM group information multiplexed using a CDM methodthrough DCI from a base station.

A UE may recognize (or determine) whether the UE is scheduled withMU-MIMO through received DCI. Accordingly, the UE may determine abundling size using the method described in the proposal 4.

Alternatively, a UE may determine whether MU-MIMO is applied based on aspecific port of a DMRS symbol or whether a CDM group is rate-matched.

Furthermore, a UE may determine a bundling size based on whether MU-MIMOis applied and a total number of layers of another MU-paired UE or theratio of the number of layers allocated thereto and a total number oflayers allocated to another UE.

Alternatively, a UE may determine a bundling size based on whether thenumber of ports in which rate matching has been indicated or the numberof CDM groups is a given value (threshold value) or more (or exceeds thegiven value) in a DMRS symbol, or may determine a bundling size based onthe ratio of the number of DMRS ports allocated thereto or the number ofREs and the number of ports in which rate matching has been indicated orthe number of REs is a given value or more (or exceeds the given value).

In this case, the bundling size may be determined when the value of anindicator indicating a bundling size of DCI is “1” through two or moreof the above-described methods.

For example, in the methods of the proposals 1 to 3, in a specific case,a bundling size is determined through the method of the proposal 4, butthe method of the proposal 4 may be performed with priority over themethods of the proposal 1 to the proposal 3.

In another embodiment of the present invention, if a candidate value setincludes 3 values, a threshold value in the proposals 1 to 3 may be setas 2 values, and a bundling size may be determined. In this case, in theproposal 4, a UE scheduled with MU-MIMO may set the smallest value ofthe 3 candidate values as a bundling size.

In the proposals 1 to 4, a threshold value, that is, a reference RB, maybe determined based on an RBG size or a subband size (used for CSIcalculation) may be used instead of an RBG in the method of determininga PRG based on an RBG size.

That is, a threshold value, that is, a reference RB, may be determinedor a PRG may be determined based on a sub-band size.

In this case, RBG values may be properly substituted with sub-bandvalues because a candidate value of an RBG and a candidate value of asub-band are different.

Both an RBG value and a sub-band value are determined as the BW of anactive BWP. Accordingly, when an RBG value is substituted with asub-band value, the BW of a BWP corresponding to the RBG value may becalculated and may be substituted with a sub-band value determined basedon the corresponding BW.

Proposal 5

If the distributed transmission of the resource allocation type 1 is setthrough scheduling DCI, contiguous virtual resource blocks (VRB) areinterleaved in an RB pair unit and distributed to the PRB domain.

Thereafter, RBs are disposed at a regulated gap size interval for eachBW size of an active BWP within an RB pair.

If VRBs are distributed, a pattern or interleaving method ofdistributing the VRBs may be performed according to various methods.

In this case, a method of implicitly determining a bundling size may bedifferent based on a unit of interleaving.

First, if a VRB is interleaved in an RB unit, a smaller value in acandidate value set configured by RRC may be set as a bundling size. Forexample, if candidate value sets are {2,4} and {2, scheduled BW}, abundling size may be determined to be “2.” If a candidate value set is{4, scheduled BW}, a bundling size may be determined to be “4.”

If the number of RBs allocated for a UE increases, there is a goodpossibility that allocated VRBs may neighbor in the PRB domain althoughthey experience interleaving. Accordingly, a bundling size of a minimum2 or 4 may use the number of DMRS symbols greater than that when abundling size is “1” in a neighbor RB. In this case, channel estimationperformance can be improved.

If a candidate value set is {4, scheduled BW}, if to select “4”, thatis, a smaller value, as a bundling size is determined to be inefficient,a network may set a bundling size to “2” by setting an indicator (orfield) indicating the bundling size of DCI to “0.”

Alternatively, in the distributed resource allocation type 1(distributed RA type 1), if a VRB is interleaved in an RB unit, abundling size may always be set to 2.

Second, if a VRB is interleaved in an RBG unit, a PRG size may be set asa configured RBG size because the PRG size of a minimum RBG unit needsto be taken into consideration in order to improve channel estimationperformance.

Alternatively, if the number of RBGs allocated to a specific UE is manyalthough interleaving is performed in an RBG unit, there is apossibility that the allocated RBGs may neighbor.

Accordingly, a threshold value may be set in the number of RBGssubstantially allocated to a UE based on the size of an active BWP BW oran interleaving method. When the number of allocated RBGs exceeds thethreshold value, a PRG size may be set like Equation 3.

PRG size=(N×set RBG size)  [Equation 3]

In Equation 3, N may have a value of “2.”

When the number of allocated RBGs does not exceeds the threshold value,a PRG size may be set as a configured RBG size.

Alternatively, as in the proposal 2-1, the PRG size may be implicitlydetermined based on the RBG size.

In another embodiment of the present invention, if the distributedresource allocation type 1 is configured through scheduling DCI and aVRB is interleaved as a PRB in an RB unit, as described above, when thenumber of RBs allocated for the data transmission of a UE increases, theprobability that the RBs may actually neighbor in the PRB domainincreases although the corresponding RBs are interleaved through aninterleaver.

In this case, a threshold value may be set in the number of allocatedRBs based on the size of an active BWP BW or an interleaving method.

If the number of allocated RBs exceeds the threshold value, when anindicator (or 1-bit field) for indicating the bundling size of DCI is“1”, a smaller value in a candidate value set configured by RRC isdetermined as a bundling size.

However, if the number of allocated RBs does not exceed the thresholdvalue, a bundling size may be set to “1” exceptionally.

In this case, if PRG=1 is included in a candidate value, a bundling sizemay be set to “1.”

Alternatively, bundling may be made off and may not be performedregardless of a value of an indicator (or 1-bit field) for indicating abundling size (i.e., PRG=1 RB).

Proposal 6

In the proposal 1 to the proposal 6, in the candidate value sets {2,scheduled BW} and {4, scheduled BW} configured by RRC for the indicator(or 1-bit field) for indicating the bundling size of DCI, when thenumber of RBs allocated for data transmission, that is, a scheduled BW,is smaller than 2 or 4, a UE and a base station may assume a scheduledBW to be smaller than 2 or 4 and set a bundling size using the methodsof the proposal 1 to the proposal 5.

FIG. 6 shows an operational flowchart of a UE which transmits andreceives data in a wireless communication system to which a methodproposed in this specification may be applied. FIG. 6 is merely forconvenience of description and does not restrict the range of thepresent invention.

Referring to FIG. 6, a corresponding UE may perform the method(s) in theembodiments of this specification. In particular, a corresponding UE maysupport the methods described in the proposal 1 to the proposal 6. InFIG. 6, related detailed description overlapping the above-describedcontents is omitted.

First, the UE may receive downlink control information (DCI) from a basestation (S6010).

In this case, the DCI may include the indicator (or 1-bit field) forindicating a bundling size, described in the proposals 1 to 6.

Thereafter, the UE may receive downlink data from the base stationthrough a downlink shared channel configured based on the downlinkcontrol information (S6020).

In this case, the bundling size of the downlink shared channel may beset as a specific number of physical resource blocks or the size of afrequency resource region allocated to the UE. In this case, a valueindicating the specific number of physical resource blocks may beincluded in a candidate value set previously configured for the downlinkshared channel.

The candidate value set may be obtained through RRC signaling, and eachcandidate value set may include the candidate values described in theproposals 1 to 6.

The bundling size may be implicitly configured through the methodsdescribed in the proposals 1 to 6 based on a value of the indicator orthe 1-bit field.

For example, as described in the proposal 1, when a value of theindicator or the 1-bit field is “0”, a bundling size may be set as avalue set by RRC.

However, when a value of the indicator or the 1-bit field is “1”, abundling size may be determined based on a result of a comparisonbetween the number of contiguous PRBs and a threshold value.

Specifically, when the number of contiguous PRBs is greater than athreshold value, a greater value of values included in a candidate valueset may be set as a bundling size. If not, the remaining value may beset as a bundling size.

In this case, the threshold value may be a value obtained by dividingthe number of resource blocks of a bandwidth for an active bandwidthpart (BWP) by 2, as described in the proposal 1.

As shown in FIGS. 8 to 11, the UE may include a processor, an RF unitand memory. The processor may control the RF unit to receive downlinkcontrol information (DCI) from the base station and to receive downlinkdata from the base station through a downlink shared channel configuredbased on the downlink control information.

In this case, the DCI may include the indicator (or 1-bit field) forindicating a bundling size, described in the proposals 1 to 6.

The bundling size of the downlink shared channel may be set as aspecific number of physical resource blocks or the size of a frequencyresource region allocated to the UE. In this case, a value indicatingthe specific number of physical resource block may be included in acandidate value set previously configured through the downlink sharedchannel.

The candidate value set may be obtained through RRC signaling, and eachcandidate value set may include the candidate values described in theproposals 1 to 6.

The bundling size may be implicitly configured through the methodsdescribed in the proposals 1 to 6 based on a value of the indicator orthe 1-bit field.

For example, as described in the proposal 1, when a value of theindicator or the 1-bit field is “0”, a bundling size may be set based ona value set by RRC.

However, when a value of the indicator or the 1-bit field is “1”, abundling size may be determined based on a result of a comparisonbetween the number of contiguous PRBs and a threshold value.

Specifically, when the number of contiguous PRBs is greater than athreshold value, a greater value of values included in a candidate valueset may be set as a bundling size. If not, the remaining value may beset as a bundling size.

In this case, the threshold value may be a value obtained by dividingthe number of resource blocks of a bandwidth for an active bandwidthpart (BWP) by 2, as described in the proposal 1.

FIG. 7 shows an operational flowchart of a base station which transmitsand receives data in a wireless communication system to which a methodproposed in this specification may be applied.

FIG. 7 is merely for convenience of description and does not restrictthe range of the present invention.

Referring to FIG. 7, a corresponding base station may perform themethod(s) described in the embodiments of this specification. Inparticular, a corresponding base station may support the methodsdescribed in the proposal 1 to the proposal 6. In FIG. 7, relateddetailed description overlapping the above-described contents isomitted.

First, a base station may transmit downlink control information (DCI) toa UE (S7010).

In this case, the DCI may include the indicator (or 1-bit field) forindicating a bundling size, described in the proposals 1 to 6.

Thereafter, the base station may transmit downlink data to the UEthrough a downlink shared channel configured based on the downlinkcontrol information (DCI) (S7020).

In this case, the DCI may include the indicator (or 1-bit field) forindicating a bundling size, described in the proposals 1 to 6.

The bundling size of the downlink shared channel may be set as aspecific number of physical resource blocks or the size of a frequencyresource region allocated to the UE. In this case, a value indicatingthe specific number of physical resource blocks may be included in acandidate value set previously configured for the downlink sharedchannel.

The candidate value set may be obtained through RRC signaling, and eachcandidate value set may include the candidate values described in theproposals 1 to 6.

The bundling size may be implicitly configured through the methodsdescribed in the proposals 1 to 6 based on a value of the indicator orthe 1-bit field.

For example, as described in the proposal 1, when a value of theindicator or the 1-bit field is “0”, a bundling size may be set as avalue set by RRC.

However, when a value of the indicator or the 1-bit field is “1”, abundling size may be determined based on a result of a comparisonbetween the number of contiguous PRBs and a threshold value.

Specifically, when the number of contiguous PRBs is greater than athreshold value, a greater value of values included in a candidate valueset may be set as a bundling size. If not, the remaining value may beset as a bundling size.

In this case, the threshold value may be a value obtained by dividingthe number of resource blocks of a bandwidth for an active bandwidthpart (BWP) by 2, as described in the proposal 1.

The base station may include a processor, an RF unit and memory, asshown in FIGS. 8 to 11. The processor may control the RF unit totransmit downlink control information (DCI) to a UE and to transmitdownlink data to the UE through a downlink shared channel configuredbased on the downlink control information.

In this case, the DCI may include the indicator (or 1-bit field) forindicating a bundling size, described in the proposals 1 to 6.

The bundling size of the downlink shared channel may be set as aspecific number of physical resource blocks or the size of a frequencyresource region allocated to the UE. In this case, a value indicatingthe specific number of physical resource block may be included in acandidate value set previously configured through the downlink sharedchannel.

The candidate value set may be obtained through RRC signaling, and eachcandidate value set may include the candidate values described in theproposals 1 to 6.

The bundling size may be implicitly configured through the methodsdescribed in the proposals 1 to 6 based on a value of the indicator orthe 1-bit field.

For example, as described in the proposal 1, when a value of theindicator or the 1-bit field is “0”, a bundling size may be set based ona value set by RRC.

However, when a value of the indicator or the 1-bit field is “1”, abundling size may be determined based on a result of a comparisonbetween the number of contiguous PRBs and a threshold value.

Specifically, when the number of contiguous PRBs is greater than athreshold value, a greater value of values included in a candidate valueset may be set as a bundling size. If not, the remaining value may beset as a bundling size.

In this case, the threshold value may be a value obtained by dividingthe number of resource blocks of a bandwidth for an active bandwidthpart (BWP) by 2, as described in the proposal 1.

General Apparatus to Which the Present Invention may be Applied

FIG. 8 illustrates a block diagram of a wireless communication apparatusaccording to an embodiment of the present invention.

Referring to FIG. 8, the wireless communication system includes an eNB(or network) 810 and a UE 820.

The eNB 810 includes a processor 811, memory 812 and a communicationmodule 813.

The processor 811 implements the functions, processes and/or methodsproposed in FIGS. 1 to 7. The layers of a wired/wireless radio interfaceprotocol may be implemented by the processor 811. The memory 812 isconnected to the processor 811 and stores various types of informationfor driving the processor 811. The communication module 813 is connectedto the processor 811 and transmits and/or receives wired/wirelesssignals.

The communication module 813 may include a radio frequency (RF) unit fortransmitting and receiving radio signals.

The UE 820 includes a processor 821, memory 822 and a communicationmodule (or RF unit) 823. The processor 821 implements the functions,processes and/or methods proposed in FIGS. 1 to 7. The layers of a radiointerface protocol may be implemented by the processor 821. The memory822 is connected to the processor 821 and stores various types ofinformation for driving the processor 821. The communication module 823is connected to the processor 821 and transmits and/or receives radiosignals.

The memory 812, 822 may be positioned inside or outside the processor811, 821 and may be connected to the processor 811, 821 by well-knownmeans.

Furthermore, the eNB 810 and/or the UE 820 may have a single antenna ormultiple antennas.

FIG. 9 illustrates a block diagram of a communication apparatusaccording to an embodiment of the present invention.

In particular, FIG. 9 is a diagram illustrating the UE of FIG. 8 morespecifically.

Referring to FIG. 9, the UE may include a processor (or digital signalprocessor (DSP) 910, an RF module (or the RF unit) 935, a powermanagement module 905, an antenna 940, a battery 955, a display 915, akeypad 920, memory 930, a subscriber identification module (SIM) card925 (this element is optional), a speaker 945 and a microphone 950. TheUE may further include a single antenna or multiple antennas.

The processor 910 implements the functions, processes and/or methodsproposed in FIGS. 1 to 7. The layers of a radio interface protocol maybe implemented by the processor.

The memory 930 is connected to the processor and stores informationrelated to an operation of the processor. The memory may be positionedinside or outside the processor and may be connected to the processor byvarious well-known means.

A user inputs command information, such as a telephone number, bypressing (or touching) a button of the keypad 920 or through voiceactivation using the microphone 950, for example. The processor receivessuch command information and performs processing so that a properfunction, such as making a phone call to the telephone number, isperformed. Operational data may be extracted from the SIM card 925 orthe memory. Furthermore, the processor may recognize and display commandinformation or driving information on the display 915, for conveniencesake.

The RF module 935 is connected to the processor and transmits and/orreceives RF signals. The processor delivers command information to theRF module so that the RF module transmits a radio signal that formsvoice communication data, for example, in order to initiatecommunication. The RF module includes a receiver and a transmitter inorder to receive and transmit radio signals. The antenna 940 functionsto transmit and receive radio signals. When a radio signal is received,the RF module delivers the radio signal so that it is processed by theprocessor, and may convert the signal into a baseband. The processedsignal may be converted into audible or readable information outputthrough the speaker 945.

FIG. 10 is a diagram showing an example of the RF module of the wirelesscommunication apparatus to which a method proposed in this specificationmay be applied.

Specifically, FIG. 10 shows an example of an RF module that may beimplemented in a frequency division duplex (FDD) system.

First, in a transmission path, the processor described in FIGS. 8 and 9processes data to be transmitted and provides an analog output signal toa transmitter 1010.

In the transmitter 1010, the analog output signal is filtered by a lowpass filter (LPF) 1011 in order to remove images caused bydigital-to-analog conversion (ADC). The signal is up-converted from abaseband to an RF by a mixer 1012 and is amplified by a variable gainamplifier (VGA) 1013. The amplified signal is filtered by a filter 1014,additionally amplified by a power amplifier (PA) 1015, routed by aduplexer(s) 1050/antenna switch(es) 1060, and transmitted through anantenna 1070.

Furthermore, in a reception path, the antenna 1070 receives signals fromthe outside and provides the received signals. The signals are routed bythe antenna switch(es) 1060/duplexers 1050 and provided to a receiver1020.

In the receiver 1020, the received signals are amplified by a low noiseamplifier (LNA) 1023, filtered by a band pass filter 1024, anddown-converted from the RF to the baseband by a mixer 1025.

The down-converted signal is filtered by a low pass filter (LPF) 1026and amplified by a VGA 1027, thereby obtaining the analog input signal.The analog input signal is provided to the processor described in FIGS.8 and 9.

Furthermore, a local oscillator (LO) 1040 generates transmission andreception LO signals and provides them to the mixer 1012 and the mixer1025, respectively.

Furthermore, a phase locked loop (PLL) 1030 receives control informationfrom the processor in order to generate transmission and reception LOsignals in proper frequencies, and provides control signals to the localoscillator 1040.

Furthermore, the circuits shown in FIG. 10 may be arrayed differentlyfrom the configuration shown in FIG. 10.

FIG. 11 is a diagram showing another example of the RF module of thewireless communication apparatus to which a method proposed in thisspecification may be applied.

Specifically, FIG. 11 shows an example of an RF module that may beimplemented in a time division duplex (TDD) system.

The transmitter 1110 and receiver 1120 of the RF module in the TDDsystem have the same structure as the transmitter and receiver of the RFmodule in the FDD system.

Hereinafter, only a different structure between the RF module of the TDDsystem and the RF module of the FDD system is described. Reference ismade to the description of FIG. 10 for the same structure.

A signal amplified by the power amplifier (PA) 1115 of the transmitteris routed through a band select switch 1150, a band pass filter (BPF)1160 and an antenna switch(es) 1170 and is transmitted through anantenna 1180.

Furthermore, in a reception path, the antenna 1180 receives signals fromthe outside and provides the received signals. The signals are routedthrough the antenna switch(es) 1170, the band pass filter 1160 and theband select switch 1150 and are provided to the receiver 1120.

In accordance with an embodiment of the present invention, there is aneffect in that overhead of control information can be reduced and abundling size can be configured.

Furthermore, in accordance with an embodiment of the present invention,there is an effect in that a bundling size can be flexibly configured orindicated through a small amount of control information.

Furthermore, in accordance with an embodiment of the present invention,there is an effect in that channel estimation performance can beimproved by increasing the number of resource blocks to which the sameprecoder is applied when a scheduled bandwidth is large.

Effects which may be obtained in the present invention are not limitedto the above-described effects, and other technical effects notdescribed above may be evidently understood by a person having ordinaryskill in the art to which the present invention pertains from thefollowing description

The method of transmitting and receiving data in a wirelesscommunication system according to the embodiments of the presentinvention has been described based on an example in which it is appliedto the 3GPP LTE/LTE-A system and the 5G system, but may be applied tovarious wireless communication systems in addition to the 3GPP LTE/LTE-Asystem and the 5G system.

1. A method of receiving data by a user terminal in a wirelesscommunication system, the method comprising: receiving, from a basestation, configuration information related to a physical resource block(PRB) bundling size of a downlink shared channel, wherein theconfiguration information comprises (i) a first bundling size setconsisting of one value among a plurality of candidate values, and (ii)a second bundling size set consisting of two values among the pluralityof candidate values; receiving, from the base station, downlink controlinformation comprising a bundling size indicator; based on the bundlingsize indicator having a first indicator value, determining the PRBbundling size as the one value in the first bundling set based on thebundling size indicator having a second indicator value, determining thePRB bundling size as one of the two values in the second bundling set,based on whether a size of contiguous scheduled PRBs in a frequencydomain exceeds a threshold that is related to a size of a bandwidth part(BWP) for the user terminal; and receiving downlink data from the basestation through the downlink shared channel configured based on the PRBbundling size.
 2. The method of claim 1, wherein the plurality ofcandidate values is equal to {2, 4, W}, where W represents the size ofthe contiguous scheduled PRBs in the frequency domain.
 3. The method ofclaim 2, wherein the first indicator value is “0” and the secondindicator value is “1”.
 4. The method of claim 1, wherein the one valuein the first bundling size set is equal to either 4 or W, where Wrepresents the size of the contiguous scheduled PRBs in the frequencydomain.
 5. The method of claim 1, wherein the two values in the secondbundling size set are equal to either {2, W} or {4, W}, where Wrepresents the size of the contiguous scheduled PRBs in the frequencydomain.
 6. The method of claim 1, wherein determining the PRB bundlingsize as the one of the two values in the second bundling set based onwhether the size of contiguous scheduled PRBs in the frequency domainexceeds the threshold comprises: based on the size of the contiguousscheduled PRBs being greater than the threshold, determining the PRBbundling size as a greater value among the two values in the secondbundling set.
 7. The method of claim 1, wherein determining the PRBbundling size as the one of the two values in the second bundling setbased on whether the size of contiguous scheduled PRBs in the frequencydomain exceeds the threshold comprises: based on the size of thecontiguous scheduled PRBs being smaller than the threshold, determiningthe PRB bundling size as a smaller value among the two values in thesecond bundling set.
 8. The method of claim 1, wherein the thresholdthat is related to the size of the BWP for the user terminal is equal tothe size of the BWP divided by
 2. 9. A method of transmitting data by abase station in a wireless communication system, the method comprising:transmitting, to a user terminal, configuration information related to aphysical resource block (PRB) bundling size of a downlink sharedchannel, wherein the configuration information comprises (i) a firstbundling size set consisting of one value among a plurality of candidatevalues, and (ii) a second bundling size set consisting of two valuesamong the plurality of candidate values; transmitting, to the userterminal, downlink control information comprising a bundling sizeindicator; and transmitting downlink data to the user terminal throughthe downlink shared channel configured based on the PRB bundling size,wherein the bundling size indicator having a first indicator valueindicates that the PRB bundling size is the one value in the firstbundling set, and wherein the bundling size indicator having a secondindicator value indicates that the PRB bundling size is one of the twovalues in the second bundling set, based on whether a size of contiguousscheduled PRBs in a frequency domain exceeds a threshold that is relatedto a size of a bandwidth part (BWP) for the user terminal.
 10. A userterminal configured to receive data in a wireless communication system,the user terminal comprising: a radio frequency (RF) module; at leastone processor, and at least one computer memory operably connectable tothe at least one processor and storing instructions that, when executed,cause the at least one processor to perform operations comprising:receiving, from a base station, configuration information related to aphysical resource block (PRB) bundling size of a downlink sharedchannel, wherein the configuration information comprises (i) a firstbundling size set consisting of one value among a plurality of candidatevalues, and (ii) a second bundling size set consisting of two valuesamong the plurality of candidate values; receiving, from the basestation, downlink control information comprising a bundling sizeindicator; based on the bundling size indicator having a first indicatorvalue, determining the PRB bundling size as the one value in the firstbundling set based on the bundling size indicator having a secondindicator value, determining the PRB bundling size as one of the twovalues in the second bundling set, based on whether a size of contiguousscheduled PRBs in a frequency domain exceeds a threshold that is relatedto a size of a bandwidth part (BWP) for the user terminal; and receivingdownlink data from the base station through the downlink shared channelconfigured based on the PRB bundling size.
 11. The user terminal ofclaim 10, wherein the plurality of candidate values is equal to {2, 4,W}, where W represents the size of the contiguous scheduled PRBs in thefrequency domain.
 12. The user terminal of claim 10, wherein the firstindicator value is “0” and the second indicator value is “1”.
 13. Theuser terminal of claim 10, wherein the one value in the first bundlingsize set is equal to either 4 or W, where W represents the size of thecontiguous scheduled PRBs in the frequency domain.
 14. The user terminalof claim 10, wherein the two values in the second bundling size set areequal to either {2, W} or {4, W}, where W represents the size of thecontiguous scheduled PRBs in the frequency domain.
 15. (canceled) 16.The user terminal of claim 10, wherein determining the PRB bundling sizeas the one of the two values in the second bundling set based on whetherthe size of contiguous scheduled PRBs in the frequency domain exceedsthe threshold comprises: based on the size of the contiguous scheduledPRBs being greater than the threshold, determining the PRB bundling sizeas a greater value among the two values in the second bundling set. 17.The user terminal of claim 10, wherein determining the PRB bundling sizeas the one of the two values in the second bundling set based on whetherthe size of contiguous scheduled PRBs in the frequency domain exceedsthe threshold comprises: based on the size of the contiguous scheduledPRBs being smaller than the threshold, determining the PRB bundling sizeas a smaller value among the two values in the second bundling set. 18.The user terminal of claim 10, wherein the threshold that is related tothe size of the BWP for the user terminal is equal to the size of theBWP divided by 2.